You can temporarily rename the table or column to another name, which is called 别名 . The use of a table alias refers to the use of a specific
SQLite
Rename the table in the statement. Renaming is a temporary change, and the name of the actual table in the database does not change.
Column aliases are used for a particular 表 The basic syntax of an alias is as follows: 列 The basic syntax of an alias is as follows: Suppose you have the following two tables. (1) the （2）另一个表是 Now, here is 表别名 Here we use C and D as Above. Let’s see one. 列别名 Here is an example of Above.
SQLite
Statement to rename a column in a table. 1.32.1. Grammar ¶
SELECT column1, column2....
FROM table_name AS alias_name
WHERE [condition];
SELECT column_name AS alias_name
FROM table_name
WHERE [condition];
1.32.2. Example ¶
COMPANY
table is as follows:sqlite> select * from COMPANY;
ID NAME AGE ADDRESS SALARY
---------- -------------------- ---------- ---------- ----------
1 Paul 32 California 20000.0
2 Allen 25 Texas 15000.0
3 Teddy 23 Norway 20000.0
4 Mark 25 Rich-Mond 65000.0
5 David 27 Texas 85000.0
6 Kim 22 South-Hall 45000.0
7 James 24 Houston 10000.0
DEPARTMENT
，如下所示：ID DEPT EMP_ID
---------- -------------------- ----------
1 IT Billing 1
2 Engineering 2
3 Finance 7
4 Engineering 3
5 Finance 4
6 Engineering 5
7 Finance 6
COMPANY
And
DEPARTMENT
Alias for the table:sqlite> SELECT C.ID, C.NAME, C.AGE, D.DEPT
FROM COMPANY AS C, DEPARTMENT AS D
WHERE C.ID = D.EMP_ID;
SQLite
Statement will produce the following result:ID NAME AGE DEPT
---------- ---------- ---------- ----------
1 Paul 32 IT Billing
2 Allen 25 Engineerin
3 Teddy 23 Engineerin
4 Mark 25 Finance
5 David 27 Engineerin
6 Kim 22 Finance
7 James 24 Finance
COMPANY_ID
Yes
ID
The alias of the column,
COMPANY_
name
``is
``name
Alias for the column:sqlite> SELECT C.ID AS COMPANY_ID, C.NAME AS COMPANY_NAME, C.AGE, D.DEPT
FROM COMPANY AS C, DEPARTMENT AS D
WHERE C.ID = D.EMP_ID;
SQLite
Statement will produce the following result:COMPANY_ID COMPANY_NAME AGE DEPT
---------- ------------ ---------- ----------
1 Paul 32 IT Billing
2 Allen 25 Engineerin
3 Teddy 23 Engineerin
4 Mark 25 Finance
5 David 27 Engineerin
6 Kim 22 Finance
7 James 24 Finance